Which does not work on JDK7 since TimSort is clever enough to detect that the ordering function is behaving inconsistently, resulting in the previously mentioned exception.

Also, this is just a bad idea:

A variant of the above method that has seen some use in languages that support sorting with user-specified comparison functions is to shuffle a list by sorting it with a comparison function that returns random values. However, this is an extremely bad method: it is very likely to produce highly non-uniform distributions, which in addition depends heavily on the sorting algorithm used.